[技术]Arizona眼睛模型 [复制链接]

简介 O{B[iy(C  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 ;k<n}shD  
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模型 n'dxa<F2|  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 01UEd8  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. )^G&p[G  

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光源 s@WF[S7D  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 > @Ux8#  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 ~y#jq,i/  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 =h`yc$ A(2  
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视网膜的散射 UR/lM,N;  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 ^>g7Kg"0  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 ' 9K4A'2[  
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脚本 t+R8{9L-  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： uP'x{Pr)  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 Z#-:zD7_  
余下的脚本计算与屈光度有关的所有参数。 l?+67cQLA  
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分析 C?UV3  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 07zbx6:t  
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脚本代码 n4albG4  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. E~=`Ac,G2  
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Dim entity As T_ENTITY @O;gKFx  
Dim op As T_OPERATION z|VQp,ra  
Dim mat As T_MODELMATERIAL _uvRC+~R  
Dim A As Double QEl:>HG  
Dim pupilDiam As Double @`qhQ  
Dim eID As Long |Rh%wJ  
Dim parID As Long +V"t'
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Dim count As Integer I8|7~jRB  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double ])dq4\Bw  
Dim tlens As Double, nlens As Double J|DID+M  
Dim curv As Double, conic As Double JEF2fro:Z  
Dim ok As Long N:#"4e  
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Sub Main !n<vN@V*3d  
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    '用户输入对话框 9{gY|2R_  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 pw^$WK  
        TextBox 220,21,40,21,.TextBox1 'default: 0 wnaT~r@U'  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 CJ*8x7-t  
        OKButton 40,91,90,21 ?GdoB7(%  
        CancelButton 190,91,90,21 sN6R0YW  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 j@jaFsX|  
        TextBox 220,49,40,21,.TextBox2 'default: 4 (#Vkk]
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    End Dialog x|#R$^4CY  
    Dim dlg As UserDialog 3`ov?T(H  
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    ok = Dialog (dlg) !J3dlUFRO  
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    If ok=0 Then    'cancel button was pressed W^}fAcQKH  
        Print "Execution cancelled." }O_kbPNw  
        End \,YF['Qq  
    End If 3I87|5V,Z  
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    'Assign accommodation and pupil diameter & use defaults if field left empty 5PY,}1`  
    If dlg.TextBox1 = "" Then d5/x2!mH8  
        A = 0           'Default accommodation hn:  
    Else >w,o|  
        A = CDbl(dlg.TextBox1) i:9f#  
    End If '&?OhSe
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    If dlg.TextBox2 = "" Then K`|%-k+D  
        pupilDiam = 4   'Default pupil diameter tI2V)i!  
    Else {)E)&lL  
        pupilDiam = CDbl(dlg.TextBox2) JI TQ3UL:W  
    End If oBfh1/<<a  
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    Print " " B@P +b*%  
    Print "Accommodation = " & A & " Diopters" aRPpDSR?l  
    Print "Pupil Diameter = " & pupilDiam & " mm" (9!$p|d*  
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    ' Calculate new parameters with accommodation _J'V5]=4  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 84xA/BRW  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens )f#raXa5+  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens 5F#Q1gP-  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens WCK;r{p%I  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens oMM+af  
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    tlens = 3.767 + 0.04*A                  'Lens thickness L9,;zkgo  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction $yd "bJK  
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    'Adjust parameters to account for accommodation N~c Y~a  
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    '*************************************************************************  58S>B'  
    'Aqueous thickness (Position of Lens) {s]yP_  
    '************************************************************************* o>(I_3J[p  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) l/(|rl#
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    GetCustomElement eID, entity +M@,CbqD  
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    parID = FindFullName( "Geometry.Arizona Eye" ) @|3PV  
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    ' Delete any shift(s) in z 7x6q:4Ep\  
    count = 0 @xKfqKoqg  
    While GetOperationCount(eID)>count Y9YE:s  
        GetOperation eID, count, op nT(Lh/  
        If op.Type="ShiftZ" Then *@2+$fgz  
            DeleteOperation eID,count [SnnOqWw  
            count=count-1 ^oykimYI-  
        End If w(>mP9Cb  
        count=count+1 ~"eQPTd  
    Wend A6ar@$MZ  
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    'Set new shift in dm;C @.ML  
    op.Type = "ShiftZ" ;nzzt~aCC  
    op.val1 = taq UbWeE,T~S  
    op.parent = parID hn$l<8=Q_  
    AddOperation eID, op e}F1ZJz  
    Print "Set aqueous humor thickness = " & taq-0.55 ,CGq_>Z  
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    '************************************************************************* mA{G: d  
    'Radius and conic constant of anterior lens G@Jl4iHug"  
    '************************************************************************* @;^7kt  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) C rA7lu'  
    GetConic eID, entity, curv, conic u~JCMM$  
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    SetConic eID, entity, 1/Rant, CCant &]d-R  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant dV~d60jOF  
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    '************************************************************************* oRp;9   
    'Radius and conic constant of posterior lens ;+86q"&n  
    '************************************************************************* #b^x!lR  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) rM|] }M=_V  
    GetConic eID, entity, curv, conic k&<cFZU  
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    SetConic eID, entity, 1/Rpost, CCpost ~s$ jiA1  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 0 It[Pa qG  
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    '************************************************************************* )&
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    'Lens thickness (Position of posterior lens surface) mN!5JZ'2  
    '************************************************************************* <'Ppu  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) vt(A?$j|A  
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    ' Delete any z-shift(s) F:3*i^ L  
    count = 0 k+D32]b@  
    While GetOperationCount(eID)>count 49e~/YY  
        GetOperation eID, count, op dn? #}^,"  
        If op.Type="ShiftZ" Then G$P|F6  
            DeleteOperation eID,count sKIpL(_I$  
            count=count-1 #z(
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        End If |=\w b^l+  
        count=count+1
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    Wend &efwfnG<  
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    'Set new z-shift }3}{}w0Y  
    op.Type = "ShiftZ" $@VQ{S  
    op.val1 = tlens c:$W5j('Z  
    op.parent = parID 8J5{}4s\f  
    AddOperation eID, op c@uNA0 p
 
    Print "Set lens thickness = " & tlens ^")SU(`  
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    '************************************************************************* 7aV(tMzd  
    'Lens index of refraction BLno/JK0}  
    '************************************************************************* .b3cn  
    eID = FindMaterial( "Lens" ) vvsQf
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    GetModelMaterial eID, mat ec$kcD!  
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    mat.Nd = nlens F74^HQ*J  
    SetModelMaterial eID, mat `.0WK  
    Print "Set lens index of refraction = " & nlens K~U5jpc  
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    '************************************************************************* "b#L8kN  
    'Pupil diameter o1dECLQa  
    '************************************************************************* e2P ds`  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) 0Ud.u  
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    'Adjust pupil diameter (trimming volume inner hole) 3T<aGW1  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" `Dn"<-9:  
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    ' Adjust pupil location to just in front of the lens Bq20U:f  
    parID = FindFullName( "Geometry.Arizona Eye" ) ~.dmfA{  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) /W vgC)  
    count = 0 AJ:(NV1=  
    While GetOperationCount(eID)>count 3~r>G  
        GetOperation eID, count, op Pd~{XM,yfW  
        If op.Type="ShiftZ" Then =Eh~ wm  
            DeleteOperation eID,count GJ3@".+6  
            count=count-1 G!^}z(Mgi  
        End If sK&[sN33  
        count=count+1 k3w(KH@  
    Wend :M |<c9I  
    op.Type = "ShiftZ" {FrcpcrQa  
    op.val1 = taq-0.01 '/ >7pB  
    op.parent = parID c(R=f+  
    AddOperation eID, op q#mw#Uw-  
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    Print "Set pupil diameter = " & pupilDiam -/7[\S  
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    'Update AZ Eye subassembly Description 1 po.Cmx  
    eID = FindFullName( "Geometry.Arizona Eye" ) c^?+"7oO0  
    GetEntity eID, entity A:?|\r  
    entity.Description = "Accommodation = " & A & "D" v'vYNh  
    SetEntity eID, entity m"r=p  
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    Update 3O'6 Ae  
    Print "DONE!" sgc
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End Sub k^Gf2%k  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： iz0GL&<  
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Accommodation = 4 Diopters J'=iEI  
Pupil Diameter = 4 mm z"vI
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Set aqueous humor thickness = 2.81 65>1f  
Set anterior lens radius = 10.4 and conic constant = -2.375869 kw gsf5[  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 UrP jZ:K'  
Set lens thickness = 3.927 T"tR*2HwSd  
Set lens index of refraction = 1.42672 EJz?GM  
Set pupil diameter = 4 z :q9~  
DONE! +'@j~\>^yJ